224 ON THE NATURE AND PRINCIPLES OF 



existence and operation, in many individuals, of 

 various debilitating causes, such as poverty, resi- 

 dence in large towns or in unwholesome dwellings, 

 sedentary occupations, dissipated habits, &c. may 

 perhaps excuse and justify this brief allusion to the 

 subject. 



The local measures by which the unnatural pres- 

 sure of the obstructed capillary blood- columns is re- 

 lieved are 



1. The escape of a portion of the compressed 

 blood through apertures occasioned either naturally, 

 by their rupture from excessive distension, or arti- 

 ficially, by acupuncture, incisions, leeches, &c. ; 



2. The escape of the liquor sanguinis through the 

 pores of the capillaries ; 



3. The use of derivatives, 



In some forms of acute inflammation, as in gas- 

 tritis and other cases in which a mucous membrane 

 is the seat of the disease, the morbidly increased 

 lateral pressure of the accumulated blood is some- 

 times spontaneously relieved by free haemorrhage, 

 the result of the rupture of the distended vessels. 

 But it is, of course, only in certain inflammatory 

 affections of the superficial structures of the body 

 that it is possible to imitate, by punctures and scari- 

 fications, this natural method of cure. 



The effusion of the more liquid portion of the 

 blood through the pores of the distended vessels 

 relieves the intensity of the compression of the 

 detained fluid almost as completely as its escape n 

 masse. And for the sake of obtaining that present 



